본 연구에서는 EBR 및 EBROG 기법으로 부착된 CFRP판과 콘크리트 모체 간 부착성능을 평가하였다. 실험 변수로는 콘크리 트 압축강도, 홈의 개수 및 깊이를 고려하였으며, 총 21개의 시편을 대상으로 단일 랩 전단 실험을 수행하였다. 실험 결과, EBROG 기법을 적용한 시편은 EBR 기법을 적용한 시편보다 최대 62% 높은 부착 강도를 보였다. 또한, 홈의 개수와 깊이가 증가할수록 부착강 도도 증가했으나, 홈이 3개일 때 가장 높은 증가율을 기록하였다. 한편, 콘크리트 압축강도가 증가할수록 부착강도도 상승했지만, 압축 강도가 가장 높은 시편에서는 오히려 부착강도 증가율이 가장 낮았다. 아울러, EBROG 기법으로 부착된 CFRP 판의 유효 변형률을 예측하는 모델을 개발하기 위해 실험 데이터를 기반으로 회귀 분석을 수행하였다. 제안된 모델의 예측값과 실험값의 비의 평균과 표준 편차는 각각 1.002 및 0.032로 나타나, 해당 모델이 유효 변형률을 정확하게 예측할 수 있음을 확인하였다.
Endosymbionts of the genus Buchnera, which belong to γ-Proteobacteria, reside in specialized cells known as bacteriocytes. In this announcement, we present the complete genome sequence of Buchnera aphidicola (Aphis gossypii) isolated from Aphis gossypii with Plantago asiatica. The genome spans 628,098 base pairs and has a GC content of 25.4%. A total of 589 CDs, 32 tRNAs, and 3 rRNAs were predicted. Interestingly, the evolutionary rate of the endosymbiont's genome, inferred from intraspecific variations, may be slower than that of the host's mitochondrial genome.
Cordyceps militaris is widely used in China, Korea, and other Asian countries as both a traditional medicinal ingredient and an edible fungus. This study aimed to optimize the growth conditions and fruiting body production of C. militaris by investigating various culture media and physical parameters such as pH, aeration, illumination, temperature, spawn materials, and oat–sawdust-based substrate formulations. After a 7-day incubation period, oats with a pH of 6.0, under sealed and illuminated conditions at 32°C, demonstrated the most effective mycelial growth. Substrates consisting of 70% oat and 30% sawdust had the shortest incubation time of 30.5 days for fruiting body formation. The basidiospores showed a typical germination pattern where the sporidium produced a single germ tube that elongated, and branched to form monokaryotic primary mycelia. In conclusion, using oats as a substrate in the cultivation of C. militaris could reduce production costs and help protect the environment.
Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum causes fowl typhoid in poultry. In this study, we isolated Salmonella from a Korean retail chicken shell egg and performed whole-genome sequencing, from which we identified one chromosome (4,659,977-bp) and two plasmids (plasmid_1: 87,506 bp and plasmid_2: 2,331 bp). The isolate serotype was confirmed to be Gallinarum, with a biovar type of Gallinarum, which was finally identified as Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum. Multilocus sequence typing confirmed that the isolate was that of sequence type 78. The antimicrobial resistance gene, aac(6')- laa, was identified on the chromosome, and 166 virulence genes were detected on the chromosome and plasmid_1.
형상기억합금(SMA)-섬유 액추에이터는 소프트 로봇 공학 및 웨어러블 기술을 포함한 다양한 분야에서 큰 주목을 받아왔다. 이러 한 부드러운 액추에이터는 SMA와 단순 직물 섬유를 결합하여 개발되었으며, K 루프와 P 루프라는 두 가지 루프 패턴으로 편직되었 다. 두 루프 모두 루프 헤드 형상으로 인해 반대 굽힘 특성으로 구별된다. 그러나 이러한 액추에이터 시트의 편직 공정에는 전문 지식 과 시간이 필요하므로 편직 루프 작동 시트의 생산 비용이 높아진다. 이 논문에서는 전압을 가할 때 큰 변형이 발생하는 SMA 직물 기 반 액추에이터의 변형을 평가하는 새로운 방법을 소개하였다. SMA 재료의 매우 비선형적인 구성 방정식으로 인해 수치 분석을 위한 분석 모델을 개발하는 것은 어렵다. 따라서 본 연구에서는 SMA 재료의 대변형을 고려하면서 SMA-섬유 액추에이터의 초기 설계에 사용할 수 있는 선형 구성 방정식을 활용하는 새로운 접근 방식을 제안하였다. 전기-기계연성 효과를 모델링할 수 있는 선형구성방적 식은 ABAQUS의 UMAT을 사용하여 구현하였다. 이 등가 단위 셀 모델(EUC)은 K-루프와 P-루프의 실험적 굽힘 작동 결과와 비교하 여 검증하였다.
Al-Mg-Si alloys are light weight and have excellent corrosion resistance, and are attracting attention as a liner material for high-pressure hydrogen containers in hydrogen fuel cell vehicles. Because it has excellent plastic hardening properties, it is also applied to car body panel materials, but it is moderate in strength, so research to improve the strength by adding Si-rich or Cu is in progress. So far, the authors have conducted research on the intergranular fracture of alloys with excessive Si addition from the macroscopic mechanical point of view, such as specimen shape. To evaluate their impact tensile properties, the split-Hopkinson bar impact test was performed using thin plate specimens of coarse and fine grain alloys of Al-Mg-X (X = Cr,Si) alloy. The effect of the shape of the specimen on the characteristics was studied through finite element method (FEM) analysis. As a result, it was found that the intergranular fracture of the alloy with excessive Si depended on the specimen width (W)/grain size (d), which can be expressed by the specimen size and grain size. As W/d decreases, the intergranular fracture transforms into a transgranular fracture. As the strain rate increases, the fracture elongation decreases, and the fracture surface of the intergranular fracture becomes more brittle. It was confirmed that intergranular fracture occurred in the high strain rate region even in materials with small grain sizes.
In the development of eco-friendly vehicles such as electric vehicles, weight reduction has become a very important design target. Seat weight reduction is very important in vehicle weight reduction. In this study, the energy absorption characteristics of Almag material, an alloy of aluminum and magnesium, and mild steel SAFH440, SAFH590, SAFC780, and SAFH980 were analyzed to obtain a true stress versus true strain curve that was correlated with the test. By performing the seat frame structure analysis using the obtained analysis material property, it was possible to compare the deformation between lightweight material, Almag and mild steel materials. In addition, it was confirmed that the weight reduction effect was 25.8% when applying Almag, an equivalent lightweight material that gives the same maximum deformation as SAFH980, a high-strength mild steel.
PURPOSES : Concrete, which is a construction material, is the most widely used compression material; however, unlike steel, it exhibits nonlinear material characteristics. Therefore, to examine the behavior of structures under the nonlinear conditions of concrete materials, one must select an appropriate numerical-analysis technique and a reasonable material model. When performing the nonlinear numerical analysis of a structure using general-purpose structural analysis software, the stress–strain curve or the Mohr–Coulomb failure criterion is typically employed to consider the nonlinear material characteristics. In this study, an efficient nonlinear numerical analysis is conducted by defining the stress–strain curves and Mohr–Coulomb parameters applicable to Strand7 to examine and design the stability of reinforced concrete structures. METHODS : This study was conducted by improving existing data. Based on the tensile region of the concrete stress–strain curve presented in a simple shape and the results of the splitting test, the proposed Mohr–Coulomb parameter was improved based on regulations stipulated in the design standards of concrete structures. The characteristics and usability of the improved material models were examined using concrete splitting tensile and bending models. RESULTS : A yield area distribution similar to that of the reference data is obtained when the Mohr–Coulomb material model is used in the numerical analysis of the concrete splitting tension, thus confirming the validity of the model. In the Mohr–Coulomb material model, nonlinear resistance continues even after the maximum reaction force occurs. However, when the stress–strain curve material model is applied, at the moment the maximum reaction force occurs, the material yields and begins to be damaged. In addition, by applying the Mohr–Coulomb material model to the bending numerical-analysis model, the magnitude of stress in the tensile region from the initial stage exceeds the yield stress defined in the stress–strain curve. CONCLUSIONS : Based on a series of examples, the usability of the proposed concrete stress–strain curve and Mohr–Coulomb parameters is confirmed. However, to obtain numerical-analysis results that are consistent with the nonlinear behavior of actual structures, nonlinear testing of reinforced concrete structures shall be conducted and material models shall be improved.
Bacillus thuringiensis (Bt) is widely used as an environmentally friendly insecticide compared to chemical insecticides. However, challenges such as difficulty in direct practical application, limited efficacy duration, and stability have been identified. To solve these issues, formulation-based research is being extensively conducted. In this study, the high insecticidal activity strain Bt IMBL-B9, identified in previous research, was subjected to large-scale cultivation using a fermentor. Subsequently, various formulations were developed through formulation processes. and characteristics such as their wettability, suspensibility and particle size were assessed to select the optimized formulation.
Understanding the behavior of soil under cyclic loading conditions is essential for assessing its response to seismic events and potential liquefaction. This study investigates the effect of non-plastic fines content (FC) on excess pore pressure generation in medium-density sand-silt mixtures subjected to strain-controlled cyclic direct simple shear (CDSS) tests. The investigation is conducted by analyzing excess pore pressure (EPP) ratios and the number of cycles to liquefaction (Ncyc-liq) under varying shear strain levels and FC values. The study uses Jumunjin sand and silica silt with FC values ranging from 0% to 40% and shear strain levels of 0.1%, 0.2%, 0.5%, and 1.0%. The findings indicate that the EPP ratio increases rapidly during loading cycles, with higher shear strain levels generating more EPP and requiring fewer cycles to reach liquefaction. At 1.0% and 0.5% shear strain levels, FC has a limited effect on Ncyc-liq. However, at a lower shear strain level of 0.2%, increasing FC from 0 to 10% reduces Ncyc-liq from 42 to 27, and as FC increases further, Ncyc-liq also increases. In summary, this study provides valuable insights into the behavior of soil under cyclic loading conditions. It highlights the significance of shear strain levels and FC values in excess pore pressure generation and liquefaction susceptibility.
This study reports an experimental and analytical exploration of concrete columns laterally confined with Fe-based shape-memory alloy (Fe-SMA) spirals. For performing experiments, Fe-SMA rebars with a 4% prestrain and diameter of 10 mm were fabricated and concrete columns with internal Fe-SMA spiral reinforcement were constructed with a diameter of 200 mm and height of 600 mm. An acrylic bar with an attached strain gauge was embedded in the center of the specimen to measure local strains. Experimental variables encompassed the Fe-SMA spiral reinforcement, spacing, and activation temperature. Uniaxial compression tests were conducted after applying active confinement to the concrete columns through electrical-resistance heating. Notably, as the Fe-SMA spiral spacing decreased, the local failure zone length and compressive fracture energy of the prepared specimens increased. Additionally, a model incorporating compressive fracture energy was proposed to predict the stress–strain behavior of the. This model, accounting for active and passive confinement effects, demonstrated accurate predictions for the experimental results of this study as well as for previously reported results.
가송이(Tricholoma bakamatsutake Hongo)는 주름버섯목(Agaricales), 송이과(Tricholomataceae)에 속 하는 외생균근성 버섯류의 하나로, 송이(T. matsutake)와 일반적인 외형이 거의 비슷하며, 송이향과 맛이 강하게 나기 때문에 이 두 균종은 쉽게 혼동되며, 실제 분류 및 계통발생학적으로도 가송이와 송이는 유연 관계가 있는 것으로 밝혀졌다. 가송이는 한국, 일본, 대만, 중국의 신갈나무 등과 같은 활엽수림에 분포하는 것으로 알려져 있으며, 최근에는 제주도 구실잣밤나무림에서 발견되었다. 가송이는 균사생장이 매우 느려 연구에 어려움이 많아 균사배양 최적 조건을 구명하고자 본 연구를 실시하였다. 온도에 따른 가송이 균주 별 균사생장 특성을 조사한 결과, 모든 균주에서 25℃에서 가장 균사생장속도가 가장 빨랐으며, 특히 3833 균주가 다른 균주에 비해 약 1.5배 빠른 것으로 조사되었다.
The fall armyworm (FAW), Spodoptera frugiperda, is an invasive pest species in Africa and Asia, which is native to the Western hemisphere. Invaded FAW was corn feeding strain. We study the developmental and biology of the corn strain FAW on the rice plants compare the result with corn feeding up to F2- generation. The development periods of F0, F1 and F2 generations of the rice-fed colony were 21.7%, 18.3% and 18.9% longer than corn-fed colony. The rice-fed colony was significantly lower in the body weight of larvae and pupae, and pre-adult survival rate and the fecundity than corn-fed colony. Our results showed that the corn strain FAW can survive and complete its life cycle by feeding rice plants up to several generations under laboratory condition, but their development and fecundity were reduced in comparison to the corn feeding colony. However, this study suggests potential impact of invaded FAW to the infestation of rice fields in Asian countries.
The onion thrips, Thrips tabaci (Thysanoptera: Thripidae), is a worldwide pest that causes serious damage to Allium crop species and acts as a vector for iris yellow spot virus (IYSV). In a previous study, we established an emamectin benzoate (EB) resistant strain (EB-R) with a 490-fold higher resistance ratio than the susceptible strain (SUS). The EB-R exhibited significantly increased transcript levels of glycine receptor alpha, glutamate-gated chloride channel (GluCl) b, and cytochrome P450 (CYP450) 6EB2 compared to SUS. To identify EB resistance-related genes that are differentially expressed genes between SUS and EB-R, we established an isogenic backcrossing strain and conducted transcriptome analysis after the 4th cycle of isogenic backcrossing. Among the 85 up-regulated genes in the transcriptome data, six cuticular protein genes showed up-regulation. Additionally, CYP450 4g15, which catalyzes the synthesis of cuticular hydrocarbons, exhibited a 6 log2-fold higher expression level in EB-R compared to SUS. Therefore, the elevated expression of genes associated with cuticle protein modification may be significantly is involved in the development of EB resistance.
콩 종실에는 레시틴, 아이소플라본, 사포닌, 루테인, 안토시아닌 및 플라보노이드와 같은 생리활성 성분과 약 40%의 단백질이 들어 있어 최근 식물성 대체 단백질의 주요 재료로 이용성이 점차 증가되고 있다. 그러나 lipoxygenase, Kunitz Trypsin Inhibitor (KTI), lectin, 7Sα′subunit 단백질 및 stachyose와 같은 알레르기를 유발시키고 품질 및 기능성을 저하시키는 성분들도 존재한다. 본 연구는 갈색 종피와 penta null 유전자형 (lox1lox2lox3tilecgy1rs2)을 가져 성숙 종실에서 lipoxygenase, KTI, lectin 및 7Sα′subunit의 4가지 단백질이 모두 없으면서 stachyose의 함량이 매우 낮은 콩 계통을 육성하기 위하여 진행되었다. 5개의 자원을 이용하여 창성된 육종집단으로부터 갈색 종피와 penta null 유전자형을 가진 6개의 F2 종자가 선발되었다. 농업형질이 양호한 계통을 선발하여 F7 계통에서 lipoxygenase, KTI, lectin 및 7Sα' subunit의 4가지 단백질에 대한 부재를 확인하였다. 선발계통은 갈색종피와 자주색 꽃 및 유한신육형이며 배꼽색은 흰색이고 성숙 자엽색은 노란색이었다. 선발계통의 경장은 68cm 정도이며 백립중은 29.2g으로 대립이었고 stachyose의 함량은 3.8g/kg으로 매우 낮았으며 수량은 2.75ton/ha 정도였다. 선발된 계통은 성숙 콩 종실에서 콩 가공적성과 품질 및 기능성을 저하시키는 lipoxygenase, KTI, lectin 및 7Sα′subunit의 4가지 단백질이 모두 없으면서 난소화성 당으로 알려진 stachyose의 함량이 매우 낮은 유색콩 품종 및 중간모본으로 이용될 수 있을 것으로 사료되었다.
The most comprehensive and particularly reliable method for non-destructively measuring the residual stress of the surface layer of metals is the sin method. When X-rays were used the relationship of sin measured on the surface layer of the processing metal did not show linearity when the sin method was used. In this case, since the effective penetration depth changes according to the changing direction of the incident X-ray, becomes a sin function. Since cannot be used as a constant, the relationship in sin cannot be linear. Therefore, in this paper, the orthogonal function method according to Warren’s diffraction theory and the basic profile of normal distribution were synthesized, and the X-ray diffraction profile was calculated and reviewed when there was a linear strain (stress) gradient on the surface. When there is a strain gradient, the X-ray diffraction profile becomes asymmetric, and as a result, the peak position, the position of half-maximum, and the centroid position show different values. The difference between the peak position and the centroid position appeared more clearly as the strain (stress) gradient became larger, and the basic profile width was smaller. The weighted average strain enables stress analysis when there is a strain (stress) gradient, based on the strain value corresponding to the centroid position of the diffracted X-rays. At the 1/5 max height of X-ray diffraction, the position where the diffracted X-ray is divided into two by drawing a straight line parallel to the background, corresponds approximately to the centroid position.